Scaling of nonaffine deformation in random semiflexible fiber networks.

Random networks of semiflexible filaments play a crucial role in the mechanics of many systems, including the cell. To understand the response of semiflexible networks to stress, a strain-based measure of nonaffine deformation is introduced and used to probe the mechanics on various scales. This measure provides a unified description of nonaffinity in both strain and rotation and indicates that the level of nonaffinity in these quantities in a given system is comparable. The degree of nonaffinity decreases as the scale of observation increases. This scaling is a power law with different exponents for length scales smaller and larger than a characteristic length scale proportional to the fiber length. The fiber bending stiffness controls the scaling at small length scales, while the large length scale scaling exponent is independent of fiber density and stiffness.